A planar RRAM cell structure is a known memory switching device. The planar structure is used to observe conversion between threshold switching and memory switching directly. A single tip electrode with a vertical RRAM cell structure is also available. The single tip bottom electrode is fabricated by reactive ion etching (RIE) to confine the filament and improve device endurance.
The uncontrolled oxygen vacancies exist with a conventional vertical RRAM cell structure. The uncontrolled oxygen vacancies lead to device instability of the vertical structured metal oxide based RRAM.
A need therefore exists for methodology enabling formation of planar or vertical RRAM tip electrodes with improved device reliability and the resulting device.